Rock drilling machine



Feb. 2, 1932. H. A. HOLMBERG 1,843,482

ROCK DRILLI'NG vMAGHIM:

Filed Nov. 5o. 1927 3 sheets-sheet' 1 HANS A. HOLMBEHG @Wonne/1j Feb.2', 1932. H. A. HOLMBERG v ROCK DRILLINQ MACHINE Filed Nov. 50, 1927:l1/want of,

@H201 um? Feb, 2, @32 H. A. HOLMBERG ROCK DRILLING MACHINE Filed Nov.30. A1927 3 Sheets-Sham 3 E m G l D. W .m OJ ai 3 m 9 L lf H uw* @MMPatented Feb. 2, 1932 HANS A. HOLMBERG, OF DENVER, COLORADO ROCKnnrLLING MACHINE Application filed November 30, 1927. Serial No.236,626.

My invention relates to rock drilling machines, and has for itsprincipal object the provision of a rock drill which requires noauxiliary apparatus, such .as an air compresso-r or the' like, for itsoperation.

Another object of my invention is to provide a rock drill thatconsumes'very little ower. p A further object is to provide a rock drilli which may be manually operated by one man when desired, thev machineautomatically holding, guiding, rotating and feeding the drill forwardas the hole 'deepens as the man manually rotates they drive shalt.

A further object is to providesuch a rock drill that is light in weightand easily porta.- ble.

A further object is to provide a rock drill which may be readilydismantled and folded into small compass for transport.

A further object is to provide a rock ydrill that permits easy removaland exchange of drill-bits.

A further object is' to provide a rock drill having self-contained meansfor feeding water or air through the drill-bit to clear the hole ofchips and dust.

Further objects and advantages appear in the details of construction,which is designed proved rock f striking position. Figure 2 is anelevation v for efliciency, simplicity and economy.

In the drawings which are appended hereto and forni a part of thisspecification, Figure 1 is an elevation of theleft side of my imdrill,showing the hammer in of the right side of my'invention, showing theposition of the hammer subsequent to striking the drill. Figure 3 is asection taken along the line 3,3 of Figure 2, except that A Figure line6-6 of Figure 10. Figure 7 is a section the hammer is here shown in itslowermost position. Figure 4 is a top plan view through the reservoirand bit-holder. Figure 5 is a top plan view of the bit-rotatingmechanism. 6 is an enlarged section taken on the taken on the line 7-7lof Figure 4. Figure 8 is a section taken along the vline 8-8of Figure2. Figure 9 is a section taken along the line 9-9 ofl Figure 8. Figure10 is a section 3 taken along the line 10-10 of Figure 8. And

Figure 11 is a section taken along the line 11-11 of Figure 8. Similarnumerals indicate similar parts in all views.

My improved rock lrillope-rates by swinging a heavy hammer in a spiralpath about a rotating driving shaft, as indicated in dotted lines inFigures 1 and 2. This hammer strikes the drill-bit at a point onthegreatest radius of said spiral path, as shown in Figure l, then isautomatically withdrawn to the smallest radius in order to clear saiddrill-bit, continu-e its rotation and accumulate momentum for anotherblow. The mechanism which guides the hammer in its spiral path forms apart of my invention and is fully described herein, together with themeans for rotating said driving shaft, rotating said drill-bit, feedingair or water through said drill-bit, automatically feeding said rockdrill forward, enabling same to be quickly retracted and folded intocompact form for transport.

The machine is fitted with the usual form of base 20, which may befastened toa suit*- able support 21 by a clamp 22. Surmounting the base20 is a guide shell 23, the sides of which are of channel section andwithign which is mounted a longitudinal feed screw 24. Two blocks 25 and26 comprise the principal frame portion of the rock drill proper. Theseblocks are adapted to slide within the channel sections of the guideshell and are preferably supported on rollers which are herein shown onthe top, side and bottom guiding surfaces of the blocks.

The blocks 25 and 26 are held in proper relation by the bars 27 and thetie-rods 28, making a rigid assembly which is longitudinally movable asa unit along the guide shell 23. An extension 29 is hinged at 30 to theupper end of the block 25, and normally maintained in an uprightposition, as shown, by the bars 27. The upper end of the extension 29 isT-shaped and supports a horizontal tubular member 31 by means of a hinge32 and a shouldered stud 33, the smaller portion of which projectsthrough a hole in the extension 29 and is' retained by a pin 34.

Thetubular member 31 is a'coinb'ined support for the drill-bit and itsrotating mechanism, and reservoir for air or water, to be fed throughsaid bit. Afxed to the body of the member 31 are front and rear endplates 35 and 36, respectively. An extension of the front end plate 35supports a chuck 37 which is bored to rotatably support the butt end ofTthe drill-bit 38. An interior groove 39 in the forward portion of thechuck 37 engages a lug 40, formed on the bit 38, permitting freerotation thereof but constraininer it to follow the reciprocation of thechuck 3f.

A retaining spring 41 covers the entering slot of the groo-ve 39 topermit the insertion or withdrawal of the bit 38 from the chuck 37, butprevent its egress during operation of the machine. r1`he bit 38 is ofthe usual hollow hexagon form except for the butt portion, which isformed cylindrically for rotation Within the chuck 37. Surrounding therear end of the chuck 37 is an anvil or dolly 42, retained in positionby a set screw. A passage 43 conveys water or air through the side wallsof the dolly and chuck,terminating at its inner end in a nozzle 44 inalinement with the central hole in the bit 38, and at its outer end in aconnection for a flexible tube 45 which communicates with the interiorof the member 31.

The bit 38 is further supported in the hub of a ratchet wheel 46, whichwheel is adapted to rotate within an extension of the front end plate 35of the tubular member 31, and which wheel is held in place therein by aclip 46er. The hub of the ratchet 46 has a hexagonal bore to fit thecontour of the bit 38, with a lon gitudinal groove to permit the passageof the lug 40.

Movement is imparted to the ratchet 46 by a pawl 47 on a stem 48,adapted to reciprocate in a lug formed on the plate 35. The opposite endof the stem 48 is fitted with a roller 49, and a coil spring 50 acts toretract the pawl 47, which is advanced by the rearward movement of atransversely reciprocating cam 51 afxed to a stem 52. This stem isguided in a lug supported by the body portion of the member 31 and itsouter end is circumferentially grooved for retention by means of a setscrew in a socket formed in an extended leg of a U-shaped mangle-rack53, which is clearly illustrated in Figure 5.

The cam 51 is in the form of an unsymmetrical pyramid, as best shown inFigure 7 each of its sides approaching the apex at a different angle.The stroke of the ratchet 46 can thus be varied by partially rotatingthe cam 51 about its axis and exposing a different face to the roller49. A stem 54 extends rearwardly from the closed end of the manglerack53 and is supported in a lug affixed to the tubular member 31. An arm 55is fastened to the rearward end of this stem and extends transversely,terminating in a loop for the engagement of a lug 56 which extendsdownward from the chuck 37, and retained thereon by a pin 57.

The mangle-rack 53, together with the cam 51 and the arm 55, isreciproeated by the rotation of an intermittent pinion 58 in a wellknownmanner. rIhe pinion 58 is keyed to the upper end of a vertical shaft 59,which is supportedon the extension 29 of the front block 25.

Motion is transmitted to the vertical shaft 59 from a longitudinalshaft60, through the bevel gears 61 and 62. The shaft 60 is supported vinthe-front block 25 and in a bracket extending upward from the rear block26, and has a bevel gear 63 keyed on its rearward end. The bevel gear 63meshes with an intermittent bevel gear 64 mounted on a transversedriving shaft 65. rlhe shaft 65 extends through and is supported in therear block 26 and has a flange 66 formed on it adjacent the gear 64.Transverse teeth on this flange engage corresponding slots in the hub ofthe gear 64, causing it to yrotate with the shaft 65. rlhe shaft 65extends beyond the gear 64, and carries adjacent the opposite end of thehub of said gear a washer 67, formed with transverse teeth on both facesand its periphery. rllhese teeth engage slots in the hub of the gear 65,and in the hub of a radial stem 68, also mounted on the shaft 65, thustransmitting the motion of the shaft to said stem. Adjoining the outerend of the hub of the stem 68 is a washer 69, having two opposite teethin its periphery only, and adjoining the outer face of this washer is acollar 70, pinned to the shaft 65, to retain the abovementioned membersin place.

Slidably mounted on the stem 68 is a sleeve 71a, forming a part of ahammer 71. Afiixed to the inner end of the sleeve 71a is a collar 72,carrying a roller 73, which is adapted to engage the periphery of astationary eccentric cam 74. This cam is supported on the hub of thegear 64 and by an extended arm 75 bolted to the block 26. Surroundingthe sleeve 71a between the fixed collar 72 and a slidable collar 76 is acoil spring 77. The collar 76 is maintained at a fixed distance from thesha-ft 65 by means of the straps 78 and 79 the latter being forked tostraddle the roller` 3. rlhe shaft or inner ends of these straps areyoked to surround the washers 67 and 69, having slots to engage theperipheral teeth of said washers. y

Near the outer end of the stem 68 is a transverse slot 80, best shown inFigures 1 and 2. A latch 81, set into a recess in the head of the hammer71 and pivoted on a pin 82, has a projecting end adapted to enter theslot 8O through an opening in the sleeve 71a. This latch is normallyheld in its engaged position by a spring 83, and its opposite endcontacts a tappet 84, which protrudes through the striking face of thehammer 71, and is loosely retained by a transverse pin.

Mounted on the shaft adjacent the right side of the block 26 is atwo-lobed cam 85, fastened tothe shaft by a through-pin 86, asillustrated in Figure 10. This cam acts on the enlarged head of a pushrod 87,`guided in a lug formed on the side of the block 26 and ispressed against the cam 85 by the springs 88. A latch 89 may be manuallythrown to hold the push rod 87 out of engagement with the cam 85, and isheld either in or out of engagement by a spring detent 90. A pawl 91 ispivoted in the lower end of the push rod 87 and adapted to actuate aratchet 92', set ina recess in the block 26 and moun-ted on a sleeve 93which loosely surrounds the feed screw 24. Movement of the ratchet 92 istransmitted to the sleeve 93 by transverse teeth formed on the forwardside of said ratchet which engage slots in one end o f an `outer sleeve94. Similar slots in the opposite end of the sleeve 94 and in thecorresponding` end of the sleeve 98 are engaged by keys formed in acollar 95, which is retained onthe sleeve 98 by set screws, locking theassembly together. The sleeves 98 and 94 have bearing in the block 26and project beyond the ends thereof. n

The rearward projection of the sleeve 98 is enlarged and recessed toguide suitable extensions of two half-nuts 96 and 97, which areinternally screw-threaded to engage the feed screw 24. When thehalf-nuts 96 and 97 are in their closed position, as shown in Figures 1,2, 3 and 6, rotation of the sleeve 93 by the ratchet 92 and cam 85, actsthrough them to move the machine along the feed Screw. When saidhalf-nuts are in their open position, as shown in Figures 10 and 11, andindicated in dotted lines in Figure 6, the machine is disconnected fromthe feed screw 24 and may be moved freely along the guide shell 23.

A disc 98 having spiral grooves for the engagement of the extensions 99and 100 of the half-nuts 96 and 97 is rotatably supported on therearward extension of the sleeve 98, in p0- sition to be easily reachedby the operator. As shown in solid lines in Figure 6, the extensions 99and 100y are at the inner ends of their correspondingk spiral grooves inthe disc 98, and the half-nuts 96 and 97 are in their closed position.

A manual quarter turn clockwise of the disc 98 will bring the extensions99 and 100 near the outer ends of the spiral grooves and spread thehalf-nuts 96 and 97 to their open position, clear of the `thread on thefeedscrew 24, as indicated in dotted lines in Figure 6. Reverse turn ofthe disc 98 will close the half nuts to their initial closed position.

Keyed tothe shaft 65 adjacent the cam 85 is a spur pinion 101, whosefunction will be hereinafter explained. Beyond this pinion is a largespur gear 102, `also keyed to the 'fr Shaft 65.. This gear meshes with apinion 103 keyed to a counter shaft 104, mounted in bearings on the bars27.

A spur gear 105, also keyed to the countershaft 104, meshes with apinion 106, keyed to the shaft of an electric motor or other convenientsource of power 107.

The countershaft 104 actuates a pump 108 by means of a crank and pitman.This pump feeds air or water as desired through a pipe 109 to theinterior of the tubular member 31 at 110, where it is stored forconveyance through the hollow bit 38, to clear chips and dust from thehole being drilled. Both ends of the shaft 65 are squared for theapplication of a hand crank when desired, as indicated in dotted linesin Figure 3. Manual operation may be accelerated by removing the gear102 and attaching an auxiliary crankshaft 111 carrying a' gear 112, asindicated in dotted lines in Figures 1 and 2, which meshes with thepinion 101. is carried in a bracket 113, bolted to the block 26. By theuse of this auxiliary shaft and gearing two or more revolutions of theshaft 65 per revolution of the hand crank 114 may be obtained.

The cycle of operations of this rock drill is as follows: Beginning withthe position shown in Figure 1, where the hammer 71 is about to strikethe dolly 42. The shaft 65 is continuously rotated, either by hand orpower through the means described, and carries with it the hammerassembly, the intermittent gear 64 and the Cam 85. As the hammer strikesthe dolly, the tappet 84 is depressed, releasing the latch 81 from theslot in the stem 68. This action permits the spring 77 to expand,forcing the collar 72, sleeve 71a and hammer 71 inward toward the shaft65 a sufficient distance so that the further rotation of the hammer 71will be clear of the dolly 42. The roller 7 8 now contacts the smallestradius of the eccentric cam 74 and continued rotation of tie assemblyacts1 to compress the spring 77 as the roller follows the increasingradius of the cam, forcing the sleeve 71a and the hammer 71 to move in acorrespondingly increasing radius and compressing the spring 77 betweenthe collars 72 and 76. .At the radius at which the hammer will alignwith the dolly 42, the slot 80 in the stem 68 aligns with the latch 81,the spring 88 causing engagement thereof. This movement of the latchalso protrudes the tappet 84, the hammer assembly thus being ready foranother cycle of operations.

Rotation of the shaft 65 also brings the intermittent bevel gear 64 intomesh with the bevel gear 68 on the shaft 60, just subsequent to the blowof the hammer 71 on the dolly 42.

Motion is thus transmitted through the gears 64 and 63, the shaft 60,the gears 61 and 62, the shaft 59, and the intermittent pinion 58 to themangle-rack 53. This gearing is so proportioned that the pinion 58 turnsone The shaft 111 revolution clockwise during the engagement of thegears 64 and 63, and between blows of the hammer.

Figure 5 shows the pinion 58 and manglerack 53 as half way through theircycle of operations. rlhe mangle-rack is in its rearmost position, thearm 55 having withdrawn the bit 38 from the bottom of the hole by meansof the lug 56, chuck 4:2 and lug 40. At the same time, the bit has beenpartially rotated by the cam 51 acting on the roller L19 and advancing'the pawl 17 and ratchet 4G. The next half revolution of the pinion 58will return the mangle-rack 57 to its forward position, advancing thebit 38 to the bottom and permitting the spring 50 to retract the pawl47. Rotation of the cam 85 causes the push-rod 87 to make ytwo strokesper revolution of the shaft 65, advancing the ratchet 92 through thepawl 91. 'llhis movement is transmitted to the half-nuts 96 and 97through the sleeves 93 and 94, thus advancing the machine along thefeed-screw 24- as the bit 38 penetrates the rock. 1f this feed is toorapid, the latch 89 n ay be thrown, holding the push-rod 87 away fromthe cam 85. 1f it is too slow, the operator may also advance thefeed-screw by meansI of the ratchet handle 115, shown in Figures 1 and2.

`When the bit has penetrated the rock the length of the feed-screw 24and it becomes necessary to retract the machine to change bits, the disc98 is given one-fourth turn clockwise, spreading the half-nuts 96 and 97clear of the feed-screw and permitting rapid withdrawal of the machine.

To dismount the machine, the bars 27 are unbolted from the frame membersand 26, the pipe 109 is disconnected and the bars 27, motor 107, pump108, and countershaft 104C are removed as a unit. The retaining pin 34:is then removed from the stud 33 and the tubular member 31, togetherwith the bitholding and rotating mechanism which it supports, are foldedat the hinge 32 to lie parallel with the extension 29, which in turn isfolded at the hinge to occupy the space vacated by the removal of thebars 27. rlhe clamp 22 may then be loosened and the base 2O removedtherefrom, the machine being now in two relatively light and compactunits.

1 desire to have it understood that the specific form of my inventionherein described and illustrated may be varied within the scope of theappended claims, without departing from the spirit thereof.

Having thus described my invention, l desire to secure by LetterslPatent and claim 1. In a rock drill the combination of a manuallyoperated drive shaft mounted in suitable supports; a hammer rotatablymounted on said shaft; a drill bit mounted for intermittent rotationabove said shaft;

means by the action of a pinion, rack, arm and chuck to draw said bitpartially from said hole and force it back into said hole before andafter each blow/of said hammer; an intermittent gear drive forautomatically advancing the drive shaft, hammer, and drill support as aunit along said support; means by fluid pressure being passed throughsaid drill bit to clear the hole after each blow of the hammer; andmeans to withdraw said drive shaft, hammer, drill support and componentparts from said work simultaneously when desired.V

v2. ln a rock drill the combination of an adjustably mounted frame;bearing members carried in said frame; a drill support longitudinallylmovable in said frame a hollow drill carried in said support; a mainshaft mounted transversely on said bearing members; a feed-screw carriedin said frame; a feed-nut engaging said feed-screw means on said frameto move said drill support forward by intermittentV rotation of saidfeednut; means operating with said screw whereby said support may bemovedV quickly away from said work; a hammer whose handle is secured onsaid main shaft and is rotatable therewith; means in said handle wherebysaid hammer may be retracted in its cycle after the blow has been struckto allow said hammer to pass the end of said drill; means to rotate saiddrill; means to introduce fluid pressure through a hollow in said drillto clear the hole being drilled; and means to rotate said main shaft asdesired.

1n a rock drill the combination of a drive shaft mounted in suitablesupports; a hammer rotatably mounted on said shaft; a hollow drill bitmounted for intermittent rotation above said shaft; means to draw saidbit partially from said hole and pass fluid pressure through said bitinto said hole while the bit is drawn back; means to force the bit backinto the hole before the next blow of the hammer; means to automaticallyadvance the component parts of the drill along the support, a portion ata time, and to wit-hdraw said mechanism from said work simultaneouslywhen desired.

et. ln a rock drill the combination of a rotatable hammer handle stemsecured on a rotating shaft; another outer sliding sleeve surroundingsaid stem, having a hammer head on the end thereof; a dog pivoted in thehammer head means to collapse'said sleeve and stem together by springtension; a pin in the face of said hammer head adapted to be forced intosaid head when the head comes into contact with the drill and to releasea dog engaged with said stem and sleeve, thereby releasing said sleevefrom said stem; and means to draw said hammer and sleeve inwardly in thecycle of rotation and force it outwardly until the cycle is completedand another blow struck byl the hammer.

5. In a rock drill the combination of a rotatable hammer secured on asleeve handle; a handle stem carried within said sleeve and secured to arotatable shaft; a spring mounted around said sleeve adapted whenreleased to draw said hammer and sleeve inwardly in its cycle ofrotation sufficient for the hammer to pass the head of the drill.

6. In a rock drill the combination of a manually-rotated drive shaftmounted in suitable support; a hammer rotatably mounted on said shaft; adrill bit mounted for intermittent rotation above said shaft in suitablebearings; means comprising a pinion; a rack and an arm attached to adrill bit chuck to draw said bit partially from said hole and force itback into said hole before and after each blow of said hammer; and anintermittent gear drive for automatically advancing n the drive shaft;hammer; drill support as a unit along said support; and means towithdraw said drive shaft; hammer; and drill support as a unit from saidwork simultaneously when desired.

7 In a rock drill the combination of a rotatably mounted drive shaft; ahammer secured for rotation on said shaft; a drill bit mounted forintermittent rotation above said drive shaft and so situated that whenthe hammer is rotated the head will strike the rear end of the bitmounting; means to force fluids through said drill bit from a source ofsupply; a pump actuated by the rotation of said drive shaft to providepressure for said fiuid; means to intermittently advance said driveshaft upon its support by the action of intermittent gears; a screw andnut by which said drive shaft is advanced; means o-n said advance driveto release the action thereof and to discontinue the advance; and meansto disassemble said device to provide a compact folding drill andsupport substantially as described.

8. In a rock drill the combination of a supporting frame; a screw insaid frame to advance a rotatable shaft and its component parts alongsaid frame; suitable bea-rings and framework upon which said drive shaftis mounted; a handle to rotate said screw as desired; a rotatable driveshaft mounted for rotation in suitable bearings; a ratchet wheelactuated by the rotation of said drive shaft adapted to rotate saidscrew; a motor mounted on said framework; intermeshing gears adapted torotate said drive shaft from said motor; another drive shaft rotatableintermittently at right angles to said main drive shaft havingintermeshing gears on the end thereof; another drive shaft at rightangles thereto and driven by said gears; a mangle-rack rotated by anintermittent gear on the end of said last-mentioned shaft; a variablecam on the end of a drive shaft integral with said mangle-rack andadapted to move therewith; a. roller adapted to Contact with said camand to move a pawl on the other end of a connecting shaft; a drill bitsupported for rotation in suitable bearings; a chuck for holding saidbit for rotation in a dolly; a ratchet for rot-ating said drill bitmounted therearound and to be actuated by said pawl; a fluid tanksupported parallel with said drill bit; means to allow fluids to beforced from said tank through said drill bit to clear the hole beingbored aft-er each blow; a hammer stem mounted on said drive shaft; ahammer mounted on a sleeve surrounding said stem; a spring to draw saidhammer inwardly in its cycle after the blow has been struck upon thechuck; a cam to acctuate the hammer in its cycle; and means in the headof said hammer to release it so that the spring may actuate it initscycle and draw it inwardly upon the stem to pass the chuck after theblow has been struck.

9. A drill comprising an adjustably mounted frame; bearing memberscarried in said frame; a drill support secured on said bearings andlongitudinally movable on said frame; a drill carried'in said support;a'

and rotatable with said main shaft to strike said drill.

10. A drill comprising a frame having suitable bearings therein; a drillsupport mounted on and movable with said bearings; a hollow drillcarried in said support; means to intermittently rotate said drill; afluid chamber mounted parallel to said drill; means to force fiuid fromsaid chamber through said drill to clear out the hole being drilled; ashaft mounted in said bearings and at right angles to said frame; meansto move said drill support and shaft in either direction on said frame;a hammer handle secured on and rotatable with said shaft; a hammerCarried on said handle and adapted to strike the head of said drill whensaid shaft is rotated; and means to move said hammer onsaid handleimmediately after each blow on the head of the drill; with other meansto move the hammer relative toits handle in order to successively strikethe head of the drill.

11. A drill comprising a frame; having a ball race therein; bea-ringscarried in said race; a drill support mounted on and movable with saidbearings; a drill carried in said support; means to intermittentlyrotate said drill; a shaft mounted in said bearings and at right anglesto said frame; means to move said drill support and shaft in eitherdirection on said frame; a hammer handle secured at one end on saidshaft and rotatable therewith; a hammer carried on said handle; aplunger carried in said bore with one end protruding beyond the strikingface of the hammer and' adapted to move a dog when said plunger is movedlongitudinally in said bore; and means to move said hammer relative toits handle between each successive blow.

l2. A drill of the Class described comprising a rock drill; a main shaftmounted adjacent said drill; a handle having one end thereoi:l securedon said shaft and carried radially around said shaft when the shaft isrotated; a hammer Carried on the :tree end portion of said handle toContact with the head of the said drill when the shaft is rotated; asleeve integral with said hammer and having; a slot therein; a Collar onthe end of said sleeve; a spiral spring Carried on said sleeve; aplunger carried in said hammer; means to release said hammer when saidplunger contacts with said drill and allows the tension of the spiralspring to expand, thus retracting said hammer and sleeve on said handle;and means to set said spiral spring as the handle and hammer are movedaround said Shaft by the rotation thereof.

In testimony whereof I have axed my signature.

HANS A. HOLMBERG.

